ML20079H073

Forwards Ltrs from Engineering Firms Supporting Spent Fuel Rack Mod at Facilities.Min Gap of 2.5 Inches Between Racks Does Not Invalidate Previous Seismic Analyses If Racks Symmetrically Loaded.Restoration of 3-inch Gap Planned

ML20079H073
Person / Time
Site:	Quad Cities
Issue date:	12/10/1982
From:	Rausch T COMMONWEALTH EDISON CO.
To:	Eisenhut D Office of Nuclear Reactor Regulation
References
5559N, NUDOCS 8212160013
Download: ML20079H073 (3)

Text

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[C^)o Commonwealth Edison

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ne First I4ational Plaza. Chicago. Ilknois

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O' Address Reply to: Post Office Box 767 N

Chicago. Illinois 60690 December 10, 1982 i

Mr. Darrell G.

Eisenhut, Director Division o f Licensing U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Quad Cities Station Units 1 and 2 Information Concerning Installed High Density Fuel Racks NRC Docket Nos. 254 and 50-265

Dear Mr. Eisenhut:

Enclosed for your information are two letters from the two engineering firms that supported our spent fuel rack modification at Quad Cities Units 1 and 2.

As discussed in these letters, a minimum gap between racks of 21/2 inches does not invalidate the seismic analyses previously perf ormed if the racas are symmetrically loaded.

Please be advised tnat it is cur intention to restore a three inch gap by moving racks as needed sometime in early 1983.

We will notify you o f any changes in our plans.

Please address any questions you may have concerning this matter to this office.

One (1) signed original and thirty-nine (39) copies of this transmittal are provided for your use.

Very truly yours, fkr^^ ^Z Thomas J. Rausch Nuclear Licensing Administrato r 1m OD cc:

Region III Inspector - Quad Cities 5559N 8212160013 821210 PDR ADOCK 05000254 P

PDR

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ESTABUSMED 1789 JOSEPH OAT C ORP OR ATIO N CHEMIC AL ENGINEERS & F ABRIC ATORS October 19, 1982 Commonwealth Edison Company One First National Plaza Post Office Box 767 Chicago, Illinois 60690 Attn:

Mr. John MacDonald Re: Quad Cities High Density Fuel Racks Oat J#2443 Gentlemen:

I have been advised that the minimum gap between the rack modules F and E; and E and G is 2.5".

The seismic analysis was based on a 3" uniform gap.

Although the gap side affects the dynamics of the rack modules, varying the gap from 3" to 21" is not expected to alter the computed response 5

by more than 20t..

Therefore arranging the fuel in storage locations l

so as to load the racks in a symmetrical manner will more than restore the kinematic factor of safety in module spacings.

Sincerely,

. _ _. ' -\\, y-

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. m, s

l K.Pg SINQi e

W.%

Vice President of Engineering KPS/kmc cc: Don Hill /NUS Corporation

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2500 Broadway / Drawer 10 / Camden. New Jersey 08104 / (609) 541-2900

CORPORATION 5430-82-99 October 25, 1982 hyassuas" Onytue em78 Mr. J.

J.

Mcdonald Commonwealth Edison Company P.O.

Box 767 Chicago, IL 60690

Subject:

Quad Cities High Density Fuel Racks Installation Concern

Reference:

Joseph Oat Corporation letter to John Mcdonald (CECO) from K.

P.

Singh (OAT), dated October 19, 1982

Dear Mr. Mcdonald:

NUS has reviewed the reference letter which addresses the dynamics of rack modules F, E and G with a varying gap between racks of 3" to 2 " and agrees that the dynamic response would not be altered by more than 20%.

Also, based on rack F being essentially full (5 empty cell locations) and rack E being symmetrically loaded and approximately 70% full, tipping analysis cases E-1, E-2, and F-1 from Table C.4 of the licensing submittal would appear to be the most representative of the present loading arrangements.

The maximum : or Y displacement from any of these cases is 0.967".

Twice this amount would still be less than 2.0 inches.

When new fuel is placed in rack G a symmetric loading sequence must also be employed.

A review of the G rack full and empty tipping analyses cases in Table 6.4 shows that all maximum X and Y displacements are less than the 0.967" value identified above.

Based on a symmetric loading and unloading sequence of the F, E and G racks being employed for the remainder on the outage, the minimum 2h" gap between racks would be adequate to prevent impact of the racks during a seismic event.

The above information may be of use to CECJ in addressing the con-cerns which-have been raised due to the as-installed between-rack gaps being less than the 3" minimum required by the seismic analysis.

Sincerely, D.

L.

Hill Project Manager DLH/bme cc:

E.

R.

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